Sam buys 2 adult tickets and 3 child tickets for $44.40.John buys 3 adult tickets and 6 child tickets for $78.How much does a child ticket and adult ticket cost?

Answer 1

2a+3c = 44.40
3a+6c = 78.00

That's the same as

2a+3c = 44.40
a+2c = 26.00

subtract and you get

a+c = 18.40

Note that we don't actually have to find the price of the individual tickets.